Fractional-order calculus has a history of over 300 years, which promotes the order of the calculus from an integer order to a fraction or a complex number. The fractional-order calculus may reflect some phenomena in the nature more authentically. In fact, an integer-order capacitor does not essentially exist, which is an element with fractional-order properties. However, most of the capacitors currently used in practice have an order close to 1, and thus the fractional order may be neglected. However, if the fractional-order properties of the capacitors may be utilized to purposely design fractional-order capacitors with different orders, capacitances and powers, a new application field of the capacitors may be opened up. In 1964, G. E Carlson, a scholar from the United States, initially proposed the concept “fractional-order capacitor” according to the definition of the fractional-order calculus, and developed a passive circuit equivalent model of a fractional-order capacitor with a specific order according to the Newton iteration method. Since then, a lot of scholars in China and abroad proposed a plurality of solutions of constructing the fractional-order capacitors by using traditional resistors, capacitors, inductors, operational amplifiers and the like. However, these solutions are only applicable to milliwat-level power, which severely restricts application of the fractional-order capacitor in various power scenarios. Also, some scholars proposed manufacturing the fractional-order capacitors based on the concept of fractal geometry and by the silicon process, which, however, may be achieved only within a specific range where the order of the capacitor is less than 1.